The Natural Selection Process in Nature
The natural selection process provides a powerful tool for problem solving. This is shown by nature and its various examples of biological entities that survive and evolve in various environments. In nature, complex combinations of traits give particular biological populations the ability to adapt, survive, and reproduce in their environments. Equally impressive is the complex, relatively rapid, and robust adaptation and relatively good interim performance that occurs amongst a population of individuals in nature in response to changes in the environment. Nature's methods for adapting biological populations to their environment and nature's method of adapting these populations to successive changes in their environments (including survival and reproduction of the fittest) provides a useful model. This model can be used to develop methods to solve a wide variety of complex problems which are generally thought to require "intelligence" to solve.
In nature, a gene is the basic functional unit by which hereditary information is passed from parents to offspring. Genes appear at particular places (called gene "loci") along molecules of deoxyribonucleic acid (DNA). DNA is a long thread-like biological molecule that has the ability to carry hereditary information and the ability to serve as a model for the production of replicas of itself. All known life forms on this planet (including bacteria, fungi, plants, animals, and humans) are based on the DNA molecule.
The so-called "genetic code" involving the DNA molecule consists of long strings (sequences) of 4 possible gene values that can appear at the various gene loci along the DNA molecule. For DNA, the 4 possible gene values refer to 4 "bases" named adenine, guanine, cytosine, and thymine (usually abbreviated as A, G, C, and T, respectively). Thus, the "genetic code" in DNA consists of a long strings such as CTCGACGGT.
A chromosome consists of numerous gene loci with a specific gene value (called an "allele") at each gene locus. The chromosome set for a human being consists of 23 pairs of chromosomes. The chromosomes together provide the information and the instructions necessary to construct and to describe one individual human being and contain about 3,000,000,000 genes. These 3,000,000,000 genes constitute the so-called "genome" for one particular human being. Complete genomes of the approximately 5,000,000,000 living human beings together constitute the entire pool of genetic information for the human species. It is known that certain gene values occurring at certain places in certain chromosomes control certain traits of the individual, including traits such as eye color, susceptibility to particular diseases, etc.
When living cells reproduce, the genetic code in DNA is read. Subsequences consisting of 3 DNA bases are used to specify one of 20 amino acids. Large biological protein molecules are, in turn, made up of anywhere from 50 to 500 or more such amino acids. Thus, this genetic code is used to specify and control the building of new living cells from amino acids.
The organisms consisting of the living cells created in this manner spend their lives attempting to deal with their environment. Some organisms do better than others in grappling with (or opposing) their environment. In particular, some organisms survive to the age of reproduction and therefore pass on their genetic make-up (chromosome string) to their offspring. In nature, the process of Darwinian natural selection causes organisms with traits that facilitate survival to the age of reproduction to pass on all or part of their genetic make-up to offspring. Over a period of time and many generations, the population as a whole evolves so that the chromosome strings in the individuals in the surviving population perpetuate traits that contribute to survival of the organism in its environment.